PSYB01H3 Chapter Notes - Chapter 8: Functional Magnetic Resonance Imaging, Ex Post Facto Law, Random Assignment
Document Summary
In many instances, we cannot directly manipulate an independent variable: gender, race, age, ethnicity, se, locale, diagnosis, personality traits, and personal history are just some examples. For these kinds of variables: experimenters must select participants that have a certain characteristic or those who have been exposed to specified events. Subject variables: the above listed treated as an independent variable. Natural treatment: naturally occurring event treated as a quasi-independent variable which can be measured but not manipulated (levels may be exposure or nonexposure) Quasiexperiment: investigates effects of a quasi-independent variable on a dependent variable (quasi meaning as if or to a degree ) True experiments would be first option but ethically and practically, quasiexperiments are needed. 2 types of quasiexperimental designs: nonequivalent-control-group-designs: have experimental and comparison groups designated before treatment occurs and are not created by random assignment, before-and-after designs: pretest and posttest but no comparison group, they are their own controls.
